Henkel Kommanditgesellschaft Auf Aktien

Gerhard Collardin Gmbh

Karl-Heinz Gottwald

Jan-Willem Brouwer

Wolf-Achim Roland

Horst-Dieter Speckmann

Winfried Wichelhaus

Joerg Riesop

Helmut Endres

Kurt Hosemann

Willi Wuest

Hubert Harth

Matthias Hamacher

Roland Morlock

Bernd Mayer

Karl-Dieter Brands

Reinhard Opitz

Raschad Mady

Reinhard Seidel

Karl Dieter Brands

Hans Gotta

Detlev Bohnhorst

Caecillie Daniel

A process for phosphating metal surfaces in which a nitrite- and nickel-free zinc-containing phosphating solution is applied to the metal surfaces which, if desired, are then rinsed and subsequently after-rinsed with an aqueous solution with a pH value of 3 to 7 which contains 0.001 to 10 g/l of one or more of the cations of Li, Cu and Ag.

Phosphating process with a metalliferous re-rinsing stage

The invention is a process for applying a nickel-free, copper-containing phosphate coating to a metal surface by contacting the metal surface with a phosphate solution containing 0.2 to 2.0 g/l zinc ions, 0.5 to 25 mg/l copper ions, and 5-30 g/l phosphate ions.

Nickel-free phosphating process

Phosphating process with a copper-containing re-rinsing stage

Process for the passivating post-treatment of phosphatized metal surfaces

Process not using chlorate or nitrite for the production of nickel and

Process for preparing zinc phosphate coatings containing manganese and

The development of sludge in phosphating baths is prevented by continuously diverting a partial volume of the baths into a separate device comprising three open chambers: an oxidation chamber where the solution is treated with an O.sub.2 -containing gas to oxidize the iron (II) of the solution of iron (III), which precipitates as phosphate; a conditioning chamber in which the iron (iii) phosphate precipitate formed in the oxidation chamber is agglomerated into a readily sedimented form; and a sedimentation chamber in which the sediment formed in the conditioning chamber is separated from the remaining liquid phosphating solution. This solution is then replenished with phosphate layer-forming components, and the replenished solution is subsequently recycled to the phosphating bath.

Process for desludging phosphating baths and device for carrying out

A method for phosphate coating zinc or nickel-zinc alloy electrolytically coated metal surfaces, in which they are exposed to a phosphating solution containing zinc, manganese, and phosphate ions, and optionally cobalt and/or nitrate ions. The method is conducted at an elevated temperature for up to slightly more than 5 seconds.

Process for phosphating electrolytically zinc-coated metals

A process for phosphating metal surfaces, particularly iron, steel and zinc-plated steel, by treating them with aqueous, acidic zinc phosphate baths at only moderately elevated temperatures in the range of from 22.degree. to 38.degree. C. The baths used have 2 to 6 g/l of Zn; 4 to 23 g/l of PO.sub.4.sup.3- ; a free acid content of 0.05 to 0.4 points; and a pH-value of 3.0 to 4.0. The ratio of Zn to PO.sub.4.sup.3- is preferably in the range from 1:2 to 1:11. The baths can advantageously contain nickel-(II)-ions, with a nickel content not exceeding a Zn:Ni ratio of 1:0.5. This process gives iron-containing zinc phosphate layers having an iron content of from 5 to 20% by weight and is particularly useful for pretreatment for subsequent cathodic electro-dip-lacquering.

Phosphating solutions and process

This invention is directed to a method for treating metal surfaces. More particularly, this invention is directed to an improved method for cleaning, scouring, and activating metal surfaces prior to phosphatization, which comprises contacting said metal surfaces with an aqueous solution comprising primary and/or secondary alkali metal or ammonium salts of orthophosphates and conventional metal cleaning components, the solution having a pH value of from about 6.3 to 8.2, said pH being lower than the pH value of solutions of the corresponding secondary orthophosphates alone having the same concentration; and containing optionally condensed phosphates in an amount corresponding to the amount necessary to soften the water hardness of the water used.

Method of treating metal surfaces prior to phosphatization

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Erftstadt, Germany

Karl-Heinz Gottwald